ATBECHDEDKESFRGBGRITLILUNLSEMCPTIESILTLVFIROMKCYAL..............................JDIM350 (Ver 2.1 Jan 2001) 1990980/0 1620000/00898409EUROPEAN PATENT APPLICATIONA320040107EP98306533.519980814EnEnEn980502919980311GB91491919970819US20040107200402199902241999087 7H 04M 11/06 A 7H 04L 12/28 BdeArchitektur,Vermittlung und Betriebsverfahren für ein KommunikationssystemenCommunication system architecture, exchange and method of operationfrArchitecure, commutateur et méthode d'opération pour système de communication2Nortel Networks Limited03029042eb/ejb/id0724 D2351 Boulevard Alfred-NobelSt. Laurent, Quebec H4S 2A9CADyke, Peter JohnFruit Hill, Cornells Lane, WiddingtonSaffron Walden, Essex CB11 3SPGBUnitt, Brian Michael2 Marshbarns, Bishops StortfordHertfordshire CM23 2QNGBLewis, Andrew Paul18 Carisbrooke RoadSt Albans, Hertfordshire AL2 3HRGBAnderson, Angelaet al00078508Nortel Networks Limited IP Law Group London RoadHarlow, Essex CM17 9NAGBATBECHCYDEDKESFIFRGBGRIEITLILUMCNLPTSEALLTLVMKROSI20040107200402

An exchange (12) has a cross-point switch that is arranged to couple data transmission between subscriber terminals (16, 18), each having a dedicated modem (34), and at least one assignable modem (148) located in the exchange (12). The exchange (12) comprises fewer assignable modems than a combined number of dedicated modems within the subscriber terminals (16, 18) and, since the cross-point switch (106) is responsive to the data transmission sent via the modems of the subscriber terminals, the cross-point switch (106) thereby acts to concentrate a ratio of dedicated modems to assignable modems.